Johnny Manziel struggled in his NFL debut Sunday but needed more help from teammates that never came in the 30-0 loss to the Cincinnati Bengals, Shanahan said. Sunday's game against the Panthers in Carolina "couldn't come quick enough" for the entire offense, Shanahan said, especially Manziel.

"I felt bad for him," Shanahan said. "I know he had a lot of pressure on him. Any time someone has that pressure, they want to go out and perform. He definitely didn't play his best, but I don't think we helped him, either."

Manziel finished 10-of-18 for 80 yards, two interceptions and a 27.3 passer rating, suffering the first shutout by a first-time starter since Tennessee's Rusty Smith in 2010. The Browns are looking for Manziel, a mobile quarterback, to find a balance between choosing when to run and when to plant and throw.

Manziel said he second-guessed himself too often Sunday. The expectation was the Browns would roll out Manziel on bootlegs to give him open space to run the offense. Shanahan called two bootlegs, in part because the Bengals tried to take that away.

Manziel has "no problem" running the ball despite his five carries for 13 yards Sunday, but the Browns know the runs won't always be there if teams force him to stay in the pocket.